This invention relates to safety systems for firearms and more particularly to firing mechanisms which incorporate a provision to prevent firing of a cartridge due to inadvertent firing pin displacement, as could be effectuated by a dropping of the firearm.
Semiautomatic pistols, such as the Colt .45 and those having similar designs, can be accidentally fired when the firing pin is forcefully displaced either by the hammer or its own inertia. For example, assume that a live round is chambered in the pistol and the hammer is positioned in either a cocked or halfcocked position. Obviously, if a sufficient impact is applied to the hammer, the sear could disengage from the searing surface of the hammer or the half cocked notch thereof, whereby the hammer would fall on the firing pin. In addition, the pistol could be dropped or otherwise forcibly contacted on its muzzle whereby the inertia of the firing pin would cause it to strike and fire the chambered cartridge. Succinctly stated, the problem with such prior art firearms is simply that the firing pin can be displaced when the trigger is not pulled.
Safety mechanisms, which include a means to manually lock and unlock the firing pin, are known in the art. However, such mechanisms do not include a means to automatically lock the firing pin in semiautomatic firearms under all conditions, save, for instance, when the trigger is pulled to fire a chambered cartridge.